Recirculating air heater



Dec. 30, 1952 E. L. SCHO'FIELD, ET AL Filed Dec. 16, 1948 4 Sheets-Sheet l l I l Y J 29 i @I 59 I l V 44 6- l -74 47 70 41 'l 2? i 3e 35 Y w 54 I l l ,sig- 2 74 f 61 58 61 59 i? i EafzLSchQQ-ezd (65 (55 w Bayard Cczvu Earl L'Scho Zd E L SCHOFIELD ETAL RECIRCULATING AIR HEATER Filed Dec.

DEG 30, 1952 E. l.. scHoFlELD ET AL 2,623,735

RECIRCULATING AIR HEATER 4 Sheets-Sheet 3 Filed Dec. 16, 1948 Dec. 30, 1952 E. L. scHor-'IELD ET AL 2,523,735

i RECIRCULATING AIR HEATER Filed Deo. 16, 1948 4 Sheets-Sheet 4 84 ff-llffww Patented Dec. 30, 1952 UNITED STATES `PATENT OFFICE RECIRCULATING AIR HEATER Earl L. Schoiieldand Bayard C. Davis, Rockford, Ill., assignors to E. Lhschoeld, Incorporated, Rockford, Ill., a corporation of `Delaware 'Application December 16,1948, Serial No. 65,678

This invention Vrelates to recirculatingair heaters especially designed* and adapted for use in motor vehicles.

The principal object of our invention is to pro- `vide a heater of generallyl improved design and.i construction with a view to increased heat eX- change eiiiciency and improved distribution and direction of the air heated, so that when heat is being used for defrostingfthere is still ample heat left for car heating, and effective defrosting, which is so essential for safe driving, is possible under even the most severe and adverse weather conditions and is'never dependent upon the drivers reserving all vofthe heaters 'discharge for that purpose alone at a sacrifice to his own pers bracket and front plate, but, what is even more important, all of the movable Working parts of the heater are quickly removable for servicing and inspection, as when the motor requires oiling if it gets noisy, or when the motor must be removed for rewinding, or the switch must be removed for replacement when it has burned out. The advantages of this removable service head are multiplied when these heaters are installed in a fleet of cabs or trucks, because in such cases the service department can arrange to have on ,l

hand a number of spare heads as standbys and `when a heater on one of the cabs or trucks get out of order it takes only a fevv minutes to substitute anotherhead and put the heater back into good working order instead of having to fg keep a cab or truck laid `up in the garage for hours (or even days) While `necessary repairs are made on theheater.

Another important feature of our heater is its Vnovel arrangement of the radiator core slidably mounted at its opposite side edges between the flanges of channel-shaped sheet metal guides provided in the opposite sides of the main housing for good support and quick and easy assembly and disassembly,` whereby to enable'convenient removal occasionally for flushing out of any sludge that has collected Ytherein or to repair any leaks that might occur, the` radiator being connectible with f the'` hot water .supply. and return hoses by nipples .which arelextended from the ra- 8 Claims. (Cl. 257-137) `diator through Vholes inv the back wall of the heater housing.

.The invention` is illustrated vin the accompanyl ing drawings, in Which- Fig. 1 is a vertical longitudinal section through `a heater made in accordance with ourfinvention;

`Fig. 2 isa side view of the removable service f head, .which` includes the easily. removable front tro,

plate of the heater. housing;

Fig. 3 isa perspective viewof the heater, ,illus- `trating the mode of `assembly ofthe service head in the heater` housing;

Fig. 4 is a perspective view of the heater housingfrom which theservice head has been removed, illustrating the mode of Vassembly of the radiatorcore in said housing;

i Fig. 5 is a `cross-section .through the heater Ain .thevertical plane of lineEi-S of Fig. 1;

Fig. 6 is a fragmentary perspective View of the rear `portion of` the Vbaie structure `forming a Vpart of the-service head, illustrating amodified orV` alternative construction in so far as the de- Yfroster sectionof said bale structure is-concerned, and

Fig. '7 is a perspective view of another heater, similar-.to the heater of Figs. 1 to 5 in all respects,

lbut havingonly one defroster outlet opening in the top :Wall .0f thehousingpin connection with which, a. Abooster fan is provided to increase the hot air` ovv `to the-windshield.

' Similar reference numerals are applied tov corresponding parts throughout the views.

Referring iirst to Figs. 1 to5, the heater comprises aho-using, indicated generally by the reference numeral 8, which is of rectangular form,

`the mainbody .portion 9 of which is made of a `single-piece of sheet metal bent to provide a top Wall I0, opposed side walls II and I2, and abottom wall I3 at therniddle portion of which the ends of the piece of sheet metal are'overlapped,

as indicated at I4 in Fig..5,.and.we1ded together.

YHoles I5 `and I6 are provided in the top wall I0 at `the rear for discharge of hotair to the left and `right hand halves of the windshieldfor ,defrosting purposes, rubber hoses, or the like, being usually inserted into theseopenings toconduct the hotair tc thewindshield, as indicated at I'I in Figs. 1 and 5. Side door openings for discharge of hotair for car heating purposesare provided in theupper portions of the rSide Walls YII and I2, as indicated at I8 and I9, grille plates 20 being preferably welded. to the inner sides of the `side walls more s or less` Vas guards for- :these openingaas indicated in Figs. 4 and 5,.and cur-ved vlouvers or doors 2l being provided as closures for said openings and, as will soon appear, also as bafes or deiiectors for directing the hot air laterally from the opposite sides of the heater. The louvers 2l are pivoted at their ends, as at 22, on Iears 23 that are bent inwardly from the side walls Il and I2 and have outwardly embossed ringer vgrip portions 24 on their edge portions for convenient operation of these louvers in either direction. The bottom wall i3 of the heater housing is perforated to provide an integral grille 25 for intake of the fresh air to be heated. A back plate 26 and front plate 21 close the open 'ends of the body portion 9 of the heater housing, the back plate being spot welded to flanges 28 and carrying studs 29 by means of which the heater is adapted to be secured to the dash of the automobile or truck in which it is installed for use, and the front plate 21 having a rearwardly projecting marginal flange3ll adapted to have a telescoping t on the front edge portion 3l of the heater housing in front of the peripheral bead 32 and to be fastened in place by self-tapping screws entered through the registering holes 33, as shown at 34 in Fig. 7. Holes 35 are provided in the back plate to permit connection of the two nipples 36 in ttings 31 provided in the back wall of the rear header tank 38 of the hot water radiator core 39,

it being understood, of course, that the present Aheater is one designed to utilize the hot water or other liquid of the motor vehicles engine'cooling system and that the nipples 36 will extend through holes in the dash and have hoses conneet-ed thereto from the engine side of the dash to conduct the heating medium to and from the radiator while it is being continuously heated by .the engine by circulation through the `jacket passages thereof. A louver or door 49, similar in design to the louvers 2|, is provided as a closure for the opening 4i in the upper portion of the front plate 21, and serves, like the side louvers 2 I,

, both as a closure and as a baliie to direct the hot ,air forwardly from the heater.

It is pivoted at its ends, as at 42, to ears 43 bent inwardly from the front plate and has a ringer grip portion 44 for moving it in either direction. Here again a grille plate 45 is provided welded to the inside of the front plate to serve more or less as a guard for the opening 4I when the louver is raised.

A suction fan 46 driven by an electric motor 41,

on whose armature shaft 43 the same is mounted,

is disposed for operation in a horizontal plane in spaced relation to and above the top of the radiator core 39, whereby when the fan is operated fresh air is drawn upwardly through the open bottom 25 of the heater housing and through the radiator core to be heated by contact with the many heat transf-er fins thereof, the air thus heated being discharged then through the front and side openings, assuming the louvers 4l) and 2| have been opened, and being also discharged onto the windshield for clefrosting thereof by way of hose connections I1. Naturally, if all of the three louvers 2l and 49 vare closed and the fan 49 yis turned on, only the defroster slots of the windvand thereby regulation of the heat output of the heater, is operable manually by a knob 59 pro- Yheater with it.

jecting from the top portion of the front plate 21. The radiator core 39 collects a certain amount of sludge in it, and the core should, tneieiore, be removed occasionally for flushing out. Our construction enables easy removal and replacement of the core, there being two channel-shaped metal guides 5i, similar to drawer guides, welded in the opposite sides of the lower portion or' the heater housing in which the core is easily slidable endwise, as illustrated in Fig. 4, into abutment with the back plate 26. it is not even necessary to remove the nipples 35 from the fittings 3l on the header tank 38, it being sunicient merely to disconnect the hot water supply and' return hose connections. The flanges e2 extending the full length of the guides 5i provide i'ull length support for the core, so that there is no danger of any damage to the thin walls thereof. Naturally, when the radiator core is removed, any leaks that might have developed in service can be easily located and repaired. rIhe header tank e3 on the front end of the radiator core carries a rubber cushion pad 5d, which is conipressed between the radiator and the iront plate 21 when the latter is assembled on the heater, whereby to insure holding the radiator pressed resilientiy against the back plate 26 and thus avoid any likelihood of clatter or rattle in the event of vibration'when the car is in motion.

Similarly to the radiator core, the service head for this heater, consisting of the motor 41, fan 46, and switch 49, is removable as a unit from the heater, the service head being carried by the front plate 2l so as to be removable from the Thus, a horizontal sheet metal shroud plate 55, which has a circular center hole te therein for the fan 4t, forms the lower part of a bracket extension on the front plate for support of the motor and fan, this shroud plate being welded with the grille 45 to the front plate by means of its downwardly bent front iange 51. A sheet metal baille structure 58 is in the top portion of the compartment above the shroud plate 55 and includes a central square pocket or boxlike portion 59 on the top wall 69 of which the motor 41 is suspended on two diametrically opposed bolts 6l, rubber cushioning grommets 62 being provided in these mountings to absorb vibration and deaden sound. An integral extension 93 of the baffle structure is welded to the front plate 21 by flanges 64 to form the upper part of the bracket extension on the front plate for support of the motor and fan, and there are also flanged foot portions 65 on the rear bottom portion or" the baille structure which are welded to the top of shroud plate 55, as illustrated in Fig. 2, to complete the tie-up of the top and bottom portions of the bracket extension. It is clear, therefore, that with this service head so easily removable the motor 41 is easily -accessible for oiling or any repairs that may be found to be necessary after the heater has been in service for some time. The switch 49 is likewise easily accessible for inspection whenever there is any voccasion for it, and if the switch burns out a new one can be substituted easily. With most other heater constructions, one cannot get at either the motor or switch without first removing and then dismantling the heater. It is easy to appreciate how the advantages of the removable service head are multiplied when a series of these heaters are installed in a neet of cabs, trucks, or rental cars, because in such cases a few standby service heads can be purchased by the concerns service department and when a heater in one of the cabs,

I5, trucks, or cars gets out'. of order, it takes only a'i'ew minutes'to remove the service fhead from thatn heater and replace it with a standby and thus put the vehicle back into service right away instead of 'losing service and revenue by having it laid up a long time for what may be a relatively minor heater repair. There are also obvious advantages from the standpoint that whatever repairs may be necessary on the service head or heads removed can be taken care of as and `when thatmay be convenient, instead of having to be rushed through at the particular time the failure of a unit occurs. The side portions of the shroud plate have downwardly bent flanges 66, which have sldable engagement on the grilles 2U for lateral stability of the service head-,relative to theheater housing. At the rear of theheater housing,.the shroud plate is slanted downwardly, as at 61, for abutment with the back plate 26, and the lower edge portion of the liange is bent forwardly, as at 68, for sled runner sliding engagement at its opposite ends on top of the top iiangesz of the channel guides 5I, so that the service head is slidable into and out of the heater housing, likea drawer, similarly as the radiator 39. Slip connectors 69 are provided on the electrical conductors 10, by means of which the motor 41 is connected with the car battery and to ground for its operation, so that removal and replacement of the service head is further facilitated. In passing, attention `is called to the rubber bumpers 69 provided on the side walls of the box-like central portion 59 of the baliie structure 58, which engage the diametrically opposite sides of the motor 41 in a plane at right angles to the diametrical plane of the bolts 6| to absorb vibration and deaden sound, the two diametrically opposed mountings 6I in the one plane and the two diametrically opposed bumpers 69 in the other plane at right angles to the iirst plane affording four-way stabilityas well as cushioning and sound deaden ing for the motor.

The shroud plate 55 with itscircular center hole 5E to receive the fan 46 forms a partition separating the upper compartment in the heater housing from the lower radiator compartment, and boosts the eiiiciency of the fan by preventing parasitic eddy currents at the periphery of the fan blades where the maximum air handlingr capacity ofthe fan is concentrated. The fresh air to be heated is, therefore, drawn upwardly through the radiator core 39 quite eicently, Iand the baie structure 58 cooperating with the louvers 2l on the sides of the heater and louver 40 on the front direct the hot air in a substantiallyhorizontal direction out into the car with the least possible loss in velocity. For this purpose the balile structure includes a horizontally extending baiie flange 19 extending transversely of the front portion of the structure behind and in spaced relation to the grille 45 in the front opening 4|, and this flange 70 is so disposed with respect Ato the louver 46 that when the louver 49 is raised to the open position, Vas shown in Fig. l, the edge portion 7| -of the louver rests on top ofl the edge portion of the iiange 'ID so that the louver 4t blocks upward travel -of the hot air discharged by the fan 46 and directs it forwardly through the opening 4I into the car for heating purposes. In a simil-ar manner, horizontally extending bafile ange 'I2 are provided on opposite sides of the baiiie structure 58 in a similar rela-A 'l2 Vblockingv upward travel of hot fair discharged by the fan and directing it with minimum lossA in velo city later-ally from the heater.

On the back of the baflie structure 58 are two ducts 14 and 'l5 extending directly upwardly from the fan to conduct hot air discharged by the fan upwardly through the openings I5 and I6, respectively,` for discharge through the iiexible hose connections l1 to the two halves of the windshield for defrosting purposes. The duct i4, it will be noticed terminates close to the horizontal plane of the top of the fan blades 45, because it is import-ant to have maximum efficiency of defrost/'ing on the leftl hand half ofthe windshieldwin front of the driver, the other duct 15" being purposely cut oli at ya higher elevation and the vertical wallor baiile t6 separating the' twoV ducts' being cut on? at that same elevation, so as' to allow some f the hot' air that might other' wise iiow through duct 15 to be entrained with the greater volume flowing upwardly through duct 14. mately sixty per cent (60%) of the available hot air to the left hand half of the windshield'and approximately forty per cent (40%) to the right hand half. However, we may slot the baie 16 vertically, as shown at 'Il on the baille Hi in Fig`.` 6, and provide an ladjustable baille plate section 18, the vertical adjustment of which will determine the heat distribution as desired, a bolt '19 being provided extending through a vhole in theplate 'i and through the slot 11 to thread in la nut St on the other side' of the bale 15 to clamp the adjustable balTle 18 in its adjusted The fact that theduct 14, which-isposition. open on its rear side, is closed by abutment with the back plate 26, asshown in Fig. 1, insures a good 'flow of hot `air to the drivers half of the windshield, substantially unaifected by the opening and closing of the louvers 2l and 4D. The other duct 'i5 is only partially enclosed, the vertical flange 3l bent diagonally relative to the rear corner of the box-like portion 59 ofthe baflie structure, as shown in Fig. 6, serving to partially isolate the duct 15 from the rest of the interior of the heater casing, enough to provide for the amount of hot :air flow to the right hand half of the windshield considered to be suicient.

of Figs. 1 to 5 but has only a single large duct.

for defrosting purposes, comparable to the duct le, and weprovide a booster fan 82 of the centrifugal type, mounted on top of the heater casing 8', having its axial inlet neck 83 in open communication with the upper end of said duct. :and having its tangential discharge necks 84 and S5 directed toward the left hand and right hand.

halves of the windshield and adapted to have ilexible hose. connections, like those shown at l1 in Figs. l and', 5, attached thereto. .A separate electric motor 35 serves to drive the squirrel type rotor of the fan 82 and has a separate control `switch therefor operable by knob 3l. The suction fan L46 inside the heater has its motor 41 controlled as before by a switch operableby a knob 5E). This heater operates otherwise the same as that of Figs. 1 to 5 The increased air .ilow through the radiator 39 induced when the This gives a distribution of `approxi-Y accepts booster fan is operated is localized'to the area of the core under the duct 'Erl that supplies the hot air vto the booster fan 82, and, consequently, there is no evidence of any drop-ofic in car heating efhciency.

It is believed the foregoing description conveys Aa good understanding of the objects and advantages of our invention. The appended claims have been drawn to cover all legitimate modifications yand adaptations.

We claim:

1. A device of the class described comprising a casing of generally rectangular form having opposed side walls in iixed relationship and back and top walls, the front being open and likewise the bottom, a radiator mounted horizontally in the open bottom of said casing, means whereby said radiator is connected with a source of heating fluid supply, a front closure removably secured to the casing, said casing having air discharge openings in the upper portion of the opposed side walls thereof above the radiator, said front closure also having an air discharge op-ening provided in the upper portion thereof above the radiator, a rotary fan for drawing air upwardly through the radiator for discharge through said openings, a motor having an armature shaft connected to and driving said fan, a substantially horizontal shroud plate in the plane of said fan having a substantially circular opening provided therein in which said fan operates, said plate being secured to said iront closure and removable therewith from said casing, and means for supporting said motor on said shroud plate for removal of the motor and fan with the shroud plate from said casing.

2. A device of the class described comprising a casing of generally rectangular form having opposed side walls in iixed relationship and back and top walis, the front being open and likewise the bottom, a radiator mounted horizontally in the open bottom oi said casing, means whereby said radiator isy connected with a source of heating fluid supply, a front closure removably secured to the casing, said casing having air discharge openings in the upper portion of the opposed side walls thereof above the radiator, said iront closure also having an air dis-charge opening provided in the upper portion th-ereoi` abovethe radiator, a rotary fan for drawing air upwardly through the radiator for discharge through said openings, a motor having an armature shaft connected to and driving said fan, a substantially horizontal shroud plate in the plane of said fan having a substantially circular opening provided therein in which said fan operates, said plate being secured to Said iront closure and removable therewith from said casing, and a baifle structure supporting said motor and ian and secured to the front closure and shroud plate ior removal from the casing with said closure, said baie structure extending circumferentially relative to the motor above the fan and serving to deflect air outwardly through the side and iront discharge openings.

3. A device of the class described comprising a. casing of generally rectangular form having opposed side walls in fixed relationship and back and top walls, the front being open and likewise the bottom, substantially horizontal guides in. said casing projecting inwardly from the lower portions of said side walls, a radiator slidably mounted in said guides so as to be removable and4 replaceable through the open front of said casingjmeans whereby said radiator is detachably connected with a sou-rice of heating iiuidv supply,Vr

a front closure removably secured to the casing, a rotary fan in said casing above said radiator for drawing air upwardly through said radiator,

1 one of said casing and closure having an air discharge openincr provided therein above the level of said radiator and on the pressure side of said fan, a horizontal shroud plate having an.

opening provided therein in the plane of said fan wherein the fan operates, said plate having lateral edge portions resting slidably on top of' said guides for support andguidance, said plate being rigidly connected to said front closure for removal therewith from said casing, a motor having an armature shaft connected to and driving said fan, and means mounting said motor on said closure and shroud plate for removal therewith from said casing'. l

a. A device of the class described comprising'` .a casing of generally rectangular form having opposed side walls and back and top walls in fixed relationship, the front being open and likewise the bottom, a radiator mounted horizontally inl the open bottom of said casing, means whereby said radiator is connected with a source of heat-v ing duid supply, a front closure removably secured to the casing having an air discharge opening provided in the upper portion thereof above the radiator, said casing having an air discharge opening in the top wall thereof adjacent the back wall, a rotary fan for drawing air upwardly through the radiator for discharge through said openings, a motor having an armature shaft connected to and driving said fan, a substantially horizontal shroud plate in the plane of said fan having a substantially circular opening provided therein in which said fan operates, said plate being secured to said front closure and removable therewith from said casing, and means forV supporting said motor on said front closure and shroud plate for removal of the'motor and fan with the shroud plate from said casing.

5. A device as set forth in claim 4, wherein the casing also has air discharge openings provided in the upper portion of the opposed side walls thereof above the radiator.

6. A heater device for automobiles and the like comprising a casing of generally rectangular form having opposed side walls and back and top walls in fixed relationship, the front being open and likewise the bottom, a radiator mounted horizontally in the open bottom of said casing, means whereby said radiator is connected with a source of heating uid for circulation through the radiator, a rotary fan for drawing air upwardly through said radiator, a motor having an armature shaft connected to and driving said fan, a substantially horizontal shroud plate in the plane of said fan having a substantially circular opening provided therein in which said fan operates, a closure member constituting the front wall of said casing and which is removably attached to said casing, said shroud plate being secured to said closure member and removable therewith, means supporting said motor on said front closure and shroud plate for removal with said front' closure and shroud plate, and an air discharge opening in a wall of said casing at the discharge side of said fan.

'7. A heater device as defined in claim 6 wherein the side walls include horizontally extending guide flanges within said casing, the upper sides of said flanges constituting a sliding support for said shroud plate.

8. A heater device as defined in claim 7 where- 9 in said radiator is removable from said casing and the under sides of said guide flanges engage said radiator for maintaining the radiator in position.

EARL L. SCHOFIELD.

BAYARD C. DAVIS.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,928,094 Darrah et al Sept. 26, 1933 2,087,160 Meyerhoefer July 13, 1937 2,093,057 Redmond Sept. 14, 1937 Number Number 

